Precombustion chamber for diesel engines



. v M, 193. F. NALLINGER 9 PRECOMBUSTION CHAMBER FOR DIESEL ENGINES FilGd Feb. 6, 1935 Patented May 31, 938

UNITED STATES"? hates r 2,118,895 PBEOOHBUSTION CHAMBER FOR DIESEL ENGINES ran Nalllnger. stoma-c cum. Daimler Benz Akticngcaellschalt. Untertnrhlieim, Germany 6, 1935, Serial No. 5,280 February (cl. res-cs) Application February 4 In Germany I 4 claims. The present invention relates to a precombus tion chamber esficially for high speed diesel en- 7 gines the cham being provided with a core piece acting as anatomizer. From the injection nozzle the fuel is squirted against the core piece which isv surrounded by a plurality of passages forwarding the fuel to the main combustion chamber from the ignition chamber. These passages are curved or, form a knee or elbow or are 10 undercut. The invention consists in that, that one branch of a passage preferably converges in the direction of the fuel delivering nozzle,---the other branch converging towards the outlet conducting to the maincombustionchamber.

As compared with the well known precombustion chambers the invention provides the advantage that the fuel jet does not cool at the cold walls of the precombustion chamber thereby providing an easier starting especially at cold times. Furthermore a softer running 'of the engine can be reached by the improved precombustion chamber.

' In order to explain more clearly the invention. reference may now be had to the accompanying 5 drawing in which Fig. 1 shows diagrammatically a precombustion chamber according to the invention in vertical section on-line l--'-l of Fig. 2 and Fig. 2 a section along 2-2 of Fig. 1.

Fig. 3 shows diagrammatically a vertical s'ec- J tion of a modification,

Fig. 4 is a section on line 4-4 of Fig. 3, and Fig. 5 is a bottom plan view of the construetional form shown in Fig. 8. I Referring to Figs. 1 and 2, a is the main com; bustion chamber, b theprecombustion chamber serving as ignition chamber and provided e. g. in the cooling jacket, and c is the fuel injection nozzle by means of which the fuel is injected in the form of a conical jet e into thev precombus- 40 tion chamber. Between the precombust'lon cham-' her and the main combustion chamber is arranged an insertion piece at, the upper portion of which is provided with an annular cavity a forming a heating insulating air space. The upper part 5 of the insertion piece is in the form of a cup h,

the bottom it of which forms a plane atomizing surface at right angles to the direction of the jet of fuel leaving the nozzle c against which surface the fuel is injected.

The insertion piece it is provided with throttling openings for establishing -communication between the precombustion chamber and the main combustion chamber. These throttling openings have a bend therein. so as to prevent 5 a straight line flow of fuel from the nomle c to assign or to Stuttgartcore .piece n which extends from the atomizing surface 1' to the. central throttle opening es, the branches e1 converging towards the axis of the fuel Jet and the branches er towards the main lo combustion chamber, towards a point situated on the axis of the core piece immediately behind the throttle opening ea. The axes of. the parts er of the throttling conduits are situated within the fuel jet-cone and converge towards the point 0 15 therein, so that the air flowing through the throttling openings into the precombustion chamber can penetrate in the,form of a wedge into the core of the fuel jet cone and produce intensive heating atomization, and mixing of the fuel with m the air.

The insertion piece it forms a heat storing part of the combustion chamber of considerable wall thickness, so that the air flowing into the precombustion chamber from the main combus-; 5 tion chamber can take up heat therefrom and. cause the fuel to be brought more rapidly to the ignition temperature.

In the drawing there are shown 5 passages, but one can also provide more or less of these pas= w .sages of round, square or otherwise formed section, in lieu of the separated passages there can be provided also uninterrupted holes, for example ,cones, the core piece being in junction with the outer part by connecting arms. 'Prefpg erably the openings er are of circular section.

In the modification, shown in Figs. 3, d and 5 the branches as are replaced by a conical annular passage n in open communication with the bores c1 and formed between theend l of the core piece up and the wall, m which is spaced therefrom and is provided with a throttle opening ea in open communication with the main combustion chamber a. The conical annular passage converges towards a point situated on' the axis of the c ore d5 piece immediately behind the throttle opening es and formsf with the bores ci a throttling connection having an angu ar bend therein between the ignition chamber and the ,main combustion chamber a.

What I claim is:

1. In an internal combustion engine receiving fuel by injection, inrcombination, a main combustion chamber, an ignition chamber having a throttle opening therein in open-communication pp with the main combustion chamber, a fuel injection nozzle arranged to inject a jet of fuel into the ignition chamber, said ignition chamber having a substantially plane atomizing surface therein arranged at right angles to the direction of the jet of fuel leaving the nozzle, a core piece extending from said atomizing surface towards the throttle opening with a plurality of throttling conduits arranged around the core piece and extending from said atomizing surface to the throttle opening for establishing communication between the interior of the ignition chamber audit the throttle opening, said throttling conduits having an angular bend therein so that the ends of the conduits extending to the atomizing surface converge towards the axis of the fuel jet and the ends of the conduits extending to the throttle opening converge towards a point situated on the axis of the core piece immediately behind the throttle opening. r

2. man internal combustion engine receiving fuel by injection, in combination, a main combustion chamber, an ignitionchamber, a fuel, injection nozzle arranged to inject a jet of fuel into the ignition chamber and an insertion piece in the ignition chamber having an atomizing surface arranged substantially at right angles to the direction of the jet of fuel leaving the nozzle and having a core piece extending from said atomizing surface with a plurality of throttling bores arranged around the core' piece and converging towards the axis of the fuel jet, said insertion piece having a wall spaced from the end of the core piece and having a conical annular passage in open communication with the throttling bores between said wall and the end of the core piece and said wall having a throttle opening in open communication with the main combustion chamber, said conical annular passage converging towards a point situated on the axis of the core piece immediately behind said throttle opening, so as to form with the throttling bores a throttling connection having an angular bend therein for establishing communication between the ignition chamber and the main combustion chamber.

3. In an internal combustion engine receiving fuel .by injection, in combination, a main combustion chamber, an ignition chamber a heat storing part of considerable wall thickness between the ignition chamber and the main combustion chamber and a fuel injection nozzle artherein, so that the air flowing through the throttling openings into the ignition chamber can penetrate in the form ofa wedge. into the core of the fuel jet cone.

4. In an internal combustion engine receiving fuel by injection, the combination as set forth in; claim 3 and in which the throttling openings are bent inside the heat storing part so that a straight line transfer of fuel through tling openings is, prevented.

. 'FRI'IZ NAHDIGER.

the throt- 35 

